Quote:
Originally Posted by CapriRacer
First, Rimex is selling a device, but they have taking some liberties with the truth to convince people to buy that device.
The first concerns "Cold Pressure". They define it differently than all the tire manufacturers define it. "Cold pressure" is the pressure in a tire when the tire hasn't been operated for some time - that is "cold".
The fact that if you set the cold pressures when the ambient temperature is - say - 50° F, then later measure the pressure when the ambient temperature is 90° F, you get a different pressure reading - is just an unfortunate fact of Physics. Rimex is trying claim that their device works off a different law of Physics - that the proper pressure in a tire is defined as occurring at a particular set of temperature and atmospherically pressure conditions - which oddly enough are different that STP (Standard Temperature and Pressure) as defined in Chemistry.
That is incorrect - and I suspect they are deliberately doing this incorrectly because their device would require more complication to do correctly.
So while there is a lot of correct physics in the article, their starting premise is incorrect.
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Thanks for clarifying that. Longacre Racing also sells a "temperature-compensating gauge" similar to what Rimex is hawking.
I think the premise is that if you want, IE: 32psi
when you are driving, the gauge will indicate a compensating pressure based on current ambient F/C.
IE: With an outside ambient of F°40, the gauge will recommend 28-30psi. About 5-10 minutes of driving, and your tires will peak out around your goal - 32psi. Something which I suspect is more important for competition, not every day street driving.
Let me know if I'm on the right path with that, or totally out to lunch, lol!
I'm simpler than that: I use a gauge that indicates actual PSI, and adjust my tires to desired pressure cold - just before sunup, car not driven since yesterday. That's my definition of 'cold' pressures.